Re: OT: What happens after ditching long distance?

On Thu, 7 Aug 2008 09:48:28 -0700 (PDT), mrdarrett@gmail.com wrote:

>On Aug 6, 2:53 pm, Jeff Liebermann <je...@cruzio.com> wrote:
>
>> There are a few tricks to setting up a coffee shop router. Email if
>> you want details.
>
>
>Is it something like this?
>http://www.howtoforge.com/wifi_hotspot_setup
>
>DD-WRT, FreeRadius, phpMyPrepaid...?
>
>Michael

[added alt.internet.wireless]

I wish I had seen that article when I was first learning to set it up.
That's close to what I'm doing. DD-WRT MySQL and FreeRadius (on an
internet connected server). I didn't know about phpMyPrepaid and will
certainly try it out quite soon. Looks like the author has gone into
business providing remote authentication:
<http://swarmhotspots.com>

However, that's not the tricks I was referring to. Briefly:

1. Use a short DHCP expire interval. 1 hour is about right. The
problem is that passerbys and transient users rapidly fill up the MAC
address table with junk. After about 256 entries, things start to
break.

2. In DD-WRT, there's a check box somewhere that controls whether the
DHCP lease table is saved to NVRAM. Don't check it. The lease table
fills up fast and can also get cluttered with stale entries. Power
cycling should be able to clear the table and start over. If it were
saved, the garbage becomes almost permanent.

3. Keep the TX power low. Far too many freeloaders in the parking
lot.

4. Put the router or access points where the customers can see the
flashing lights. If they can see the traffic moving, they don't ask
the staff questions like "is the internet down".

5. Setup a reset button that cycles the power to the DSL modem,
router, and wireless. X10 controllers are tolerable. So is a common
AC power strip. The idea is to make it easy for the staff to cycle
the power and not force them to unplug wall warts and such.

I hope this helps.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Aug 8, 10:10 am, Jeff Liebermann <je...@cruzio.com> wrote:
> On Thu, 7 Aug 2008 09:48:28 -0700 (PDT), mrdarr...@gmail.com wrote:
> >On Aug 6, 2:53 pm, Jeff Liebermann <je...@cruzio.com> wrote:
>
> >> There are a few tricks to setting up a coffee shop router. Email if
> >> you want details.
>
> >Is it something like this?
> >http://www.howtoforge.com/wifi_hotspot_setup
>
> >DD-WRT, FreeRadius, phpMyPrepaid...?
>
> >Michael
>
> [added alt.internet.wireless]
>
> I wish I had seen that article when I was first learning to set it up.
> That's close to what I'm doing. DD-WRT MySQL and FreeRadius (on an
> internet connected server). I didn't know about phpMyPrepaid and will
> certainly try it out quite soon. Looks like the author has gone into
> business providing remote authentication:
> <http://swarmhotspots.com>
>
> However, that's not the tricks I was referring to. Briefly:
>
> 1. Use a short DHCP expire interval. 1 hour is about right. The
> problem is that passerbys and transient users rapidly fill up the MAC
> address table with junk. After about 256 entries, things start to
> break.
>
> 2. In DD-WRT, there's a check box somewhere that controls whether the
> DHCP lease table is saved to NVRAM. Don't check it. The lease table
> fills up fast and can also get cluttered with stale entries. Power
> cycling should be able to clear the table and start over. If it were
> saved, the garbage becomes almost permanent.
>
> 3. Keep the TX power low. Far too many freeloaders in the parking
> lot.
>
> 4. Put the router or access points where the customers can see the
> flashing lights. If they can see the traffic moving, they don't ask
> the staff questions like "is the internet down".
>
> 5. Setup a reset button that cycles the power to the DSL modem,
> router, and wireless. X10 controllers are tolerable. So is a common
> AC power strip. The idea is to make it easy for the staff to cycle
> the power and not force them to unplug wall warts and such.
>
> I hope this helps.
>
> --
> Jeff Liebermann je...@cruzio.com
> 150 Felker St #D http://www.LearnByDestroying.com
> Santa Cruz CA 95060http://802.11junk.com
> Skype: JeffLiebermann AE6KS 831-336-2558



Ah, thanks. I wasn't aware of (1) and (2).

For (5), since you're using a Linux box, does it matter if it's
powered down properly or not? 'shutdown -h now' and all that...?

Michael

On Fri, 8 Aug 2008 14:50:36 -0700 (PDT), mrdarrett@gmail.com wrote:

>On Aug 8, 10:10 am, Jeff Liebermann <je...@cruzio.com> wrote:

>> 5. Setup a reset button that cycles the power to the DSL modem,
>> router, and wireless. X10 controllers are tolerable. So is a common
>> AC power strip. The idea is to make it easy for the staff to cycle
>> the power and not force them to unplug wall warts and such.

>For (5), since you're using a Linux box, does it matter if it's
>powered down properly or not? 'shutdown -h now' and all that...?
>Michael

There are two types of RADIUS servers that I'm tinkering with. One is
a local RADIUS server at the coffee shop location. It doesn't have a
keyboard on which to type the proper shutdown incantation. All admin
is done with SSH or HTML. I make sure that write caching to the hard
disk is disabled. EXT3 is a journaling filesystem, which recovers
nicely from unexpected power failures. I'm currently using a PC104
SBC (single board computah) for the RADIUS server, running from a 2GB
CF (compact flash) card. I twice managed to trash some syslog junk
that I was storing locally, but otherwise, it seems reliable. One
location has utility power problems and I get about 5 reboots per
week. Good enough, but with only one live system, it's really too
soon to tell.

So far, I haven't lost any "sectors" on the CF cards. In anticipation
of a CF card drive failure, I have 2 spares sitting next to each
machine. When all else fails, or I can't login remotely, I have them
swap CF cards. That causes lots of problems with dropped connections
and authentication failures, so I save that for special occasions.

I'm also working on a mini-ITX version, as my supply of cheap PC-104
boards has hit zero.
<http://www.mini-itx.com>

The other type of RADIUS server is located at my office and eventually
in an ISP's server farm. The customer does not power down this RADIUS
server. It services multiple customers, stays up all the time, and is
not expected to survive a graceless power failure (which it will do
quite nicely anyway).

However, neither of these fit my recommendation for easy power
cycling. It's not intended to power cycle a server, just the DSL
modem, router, and wireless devices. Such commodity hardware is not
particularly known for high uptime, and will sometimes hang. I just
want to make it easy for the coffee shop owner to recover.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Aug 9, 10:30 am, Jeff Liebermann <je...@cruzio.com> wrote:
> On Fri, 8 Aug 2008 14:50:36 -0700 (PDT), mrdarr...@gmail.com wrote:
> >On Aug 8, 10:10 am, Jeff Liebermann <je...@cruzio.com> wrote:
> >> 5. Setup a reset button that cycles the power to the DSL modem,
> >> router, and wireless. X10 controllers are tolerable. So is a common
> >> AC power strip. The idea is to make it easy for the staff to cycle
> >> the power and not force them to unplug wall warts and such.
> >For (5), since you're using a Linux box, does it matter if it's
> >powered down properly or not? 'shutdown -h now' and all that...?
> >Michael
>
> There are two types of RADIUS servers that I'm tinkering with. One is
> a local RADIUS server at the coffee shop location. It doesn't have a
> keyboard on which to type the proper shutdown incantation. All admin
> is done with SSH or HTML. I make sure that write caching to the hard
> disk is disabled. EXT3 is a journaling filesystem, which recovers
> nicely from unexpected power failures. I'm currently using a PC104
> SBC (single board computah) for the RADIUS server, running from a 2GB
> CF (compact flash) card. I twice managed to trash some syslog junk
> that I was storing locally, but otherwise, it seems reliable. One
> location has utility power problems and I get about 5 reboots per
> week. Good enough, but with only one live system, it's really too
> soon to tell.
>
> So far, I haven't lost any "sectors" on the CF cards. In anticipation
> of a CF card drive failure, I have 2 spares sitting next to each
> machine. When all else fails, or I can't login remotely, I have them
> swap CF cards. That causes lots of problems with dropped connections
> and authentication failures, so I save that for special occasions.
>
> I'm also working on a mini-ITX version, as my supply of cheap PC-104
> boards has hit zero.
> <http://www.mini-itx.com>


How much do those PC-104 boards / systems cost?

Disable write-caching, use ext3... I'll keep that in mind.

Thanks,

Michael

On Sat, 9 Aug 2008 21:38:34 -0700 (PDT), mrdarrett@gmail.com wrote:

>How much do those PC-104 boards / systems cost?

Zero. I got them free from a failed dot com. I started with about 30
boards and used them for various projects. I'm down to 4 which I'll
keep for spares and tinkering. Kontron board with a Pentium 166MHz
and 512Mbytes ram, which is about right. No fan needed. I wouldn't
have used these, except that the price is right. The big headaches
are all the adapters and creative wiring necessary to interface the
boards to kbd, monitor, serial, ethernet, etc.

>Disable write-caching, use ext3... I'll keep that in mind.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558